"It is difficult to live with people because it is so difficult to be silent. And not against him who is repugnant to us are we most unfair, but against him who is no concern of ours."

"The man of knowledge must be able not only to love his enemies but also to hate his friends."

"All truly great thoughts are conceived by walking."

"When virtue has slept, she will get up more refreshed."

"Out of passions grow opinions, mental sloth lets these rigidify into convictions."

"Digressions, objections, delight in mockery, carefree mistrust are signs of health; everything unconditional belongs in pathology."

"Nothing is worth more than this day."

"Beauty is the first test; there is no permanent place in the world for ugly mathematics."

"When you encounter difficulties and contradictions, do not try to break them, but bend them with gentleness and time."

"For without belittling the courage with which men have died, we should not forget those acts of courage with which men have lived."

"It does not matter how slowly you go, so long as you do not stop."

"If you live long enough, the venerability factor creeps in; first, you get accused of things you never did, and later, credited for virtues you never had."